scholarly journals Modeling an Alternate Operational Ground Source Heat Pump for Combined Space Heating and Domestic Hot Water Power Sizing

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2120
Author(s):  
Kaiser Ahmed ◽  
Jevgeni Fadejev ◽  
Jarek Kurnitski

This study developed an alternate operational control system for ground source heat pumps (GSHP), which was applied to determine combined space heating and domestic hot water (DHW) power equations at design temperature. A domestic GSHP with an alternate control system was implemented in a whole building simulation model following the heat deficiency for space heating based on degree minute counting. A simulated GSHP system with 200 L storage tank resulted in 13%–26% power reduction compared to the calculation of the same system with existing European standards, which required separate space heating and DHW power calculation. The periodic operation utilized the thermal mass of the building with the same effect in the case of light and heavy-weight building because of the very short cycle of 30 min. Room temperatures dropped during the DHW heating cycle but kept within comfort range. The developed equations predict the total power as a function of occupancy, peak and average DHW consumption with variations of 0%–2.2% compared to the simulated results. DHW heating added the total power in modern low energy buildings by 21%–41% and 13%–26% at design temperatures of −15 °C and −26 °C, respectively. Internal heat gains reduced the power so that the reduction effect compensated the effect of DHW heating in the case of a house occupied by three people. The equations could be used for power sizing of any heat pump types, which has alternate operation principle and hydronic heating system.

Author(s):  
Wessam El-Baz ◽  
Peter Tzscheutschler ◽  
Ulrich Wagner

There is a continuous growth of heat pump installations in residential buildings in Germany. The heat pumps were not only used for space heating and domestic hot water consumption but also to offer flexibility to the grid. the high coefficient of performance and the low cost of heat storages made the heat pumps an optimal candidate for the power to heat applications. Thus, several questions are raised about the optimal integration and control of the heat pump system with buffer storages to maximize its operation efficiency and minimize the operation costs. In this paper, an experimental investigation is performed to study the performance of a ground source heat pump (GSHP) with a combi-storage under several configurations and control factors. The experiments were performed on an innovative modular testbed that is capable of emulating a ground source to provide the heat pump with different temperature levels at different times of the day. Moreover, it can emulate the different building loads such as the space heating load and the domestic hot water consumption in real-time. The data gathered from the testbed and different experimental studies were used to develop a simulation model based on Modelica that can accurately simulate the dynamics of a GSHP in a building. The model was validated based on different metrics. Energetically, the difference between the developed model and the measured values was only 3.08\% and 4.18\% for the heat generation and electricity consumption, respectively.


2014 ◽  
Vol 126 ◽  
pp. 113-122 ◽  
Author(s):  
Wei Wu ◽  
Tian You ◽  
Baolong Wang ◽  
Wenxing Shi ◽  
Xianting Li

Solar Energy ◽  
2020 ◽  
Vol 199 ◽  
pp. 347-359 ◽  
Author(s):  
Siyuan Ran ◽  
Xianting Li ◽  
Wei Xu ◽  
Baolong Wang

2021 ◽  
Vol 25 (1) ◽  
pp. 840-852
Author(s):  
Agata Witkowska ◽  
Dorota Anna Krawczyk ◽  
Antonio Rodero

Abstract Becoming the world’s first climate-neutral continent by 2050 is currently the most ambitious European goal. Heat pumps are the example of the key technology, which could help to achieve the aim by heating, cooling and domestic hot water (DHW) preparation in an ecological and energy-efficient way. This article characterized a heat pump market in Europe between 2009 and 2020 with a special regard to France, Spain, Poland and Lithuania, for which a more detailed study was presented. The analysis was performed primarily on the grounds of statistics data provided by the European Heat Pump Association (EHPA), which determined the number of heat pumps sold based on standard questionnaires from national heat pump associations, statistical offices and research institutes. The highest number of heat pump sold in analysed period of time was recorded in France, Italy, Sweden, Norway, Germany and Spain. Poland was in the middle of the list, while Lithuania was one of the last countries. Considering the number of heat pumps sold per 1000 households, Norway was the clear leader, followed by Estonia, Finland, Sweden and Denmark. Lithuania was placed 12th, while Poland was only 18th. In terms of the type of lower and upper heat source, air-to-water and air-to-air heat pumps were the most popular choices, while ground source heat pumps were the least popular. The development of the heat pump market has been influenced by social, environmental, economic and technological factors.


Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1752 ◽  
Author(s):  
Jeong Soo Shin ◽  
Jong Woo Park ◽  
Sean Hay Kim

We propose an integrated geothermal system that consists of air-conditioning and hot water service ground source heat pumps, both of which share a ground water loop. The proposed system increases the COP of the service hot water ground source heat pump by recovering the condensation heat of the air-conditioning ground source heat pump as an evaporator heat source for the hot water service ground source heat pump. Eventually this integration expands the scope and capacity of the evaporator source in addition to the underground water of heat exchangers, which also leads to increase the COP of the air-conditioning ground source heat pump. The integrated geothermal heat pump system was installed in a hotel, and then data were measured for a limited period due to the hotel’s ongoing business activities. A TRNSYS simulation model has been developed as a baseline, and the baseline has been calibrated with the measured data. By running one-year simulations, it turns out that the annual electricity use for heating and cooling, and service hot water was reduced by 19.1% in the cooling season, and by 9.6% in the heating season, with respect to the conventional configuration in which the air-conditioning heat pump and hot water service heat pump work individually on their own ground loops.


Author(s):  
Robert L. Reid

A solar house in Knoxville, Tennessee has been operating for thirty years providing space heating and domestic hot water. The active system with air collectors and rock storage and heat pump back up has required minimal maintenance. Using data from sub-meters, the auxiliary and operating energy have been compared for the first three years of operation and the last eight years. There appears to be little or no degradation in performance during the thirty-year period.


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